Observatorio de I+D+i UPM

Memorias de investigación
Research Publications in journals:
Eigenmodes of a Counter-Rotating Vortex Dipole
Year:2008
Research Areas
  • Naval engineering
Information
Abstract
Highly resolved solutions of the two-dimensional incompressible Navier¿Stokes and continuity equations describing the evolution of a counter-rotating pair of vortices have been obtained accurately and efficiently by spectral-collocation methods and an eigenvalue decomposition algorithm. Such solutions have formed the basic state for subsequent three-dimensional biglobal-eigenvalue-problem linear-instability analyses, which monitor the modal response of these vortical systems to small-amplitude perturbations, periodic along the homogeneous axial spatial direction, without the need to invoke an assumption of azimuthal spatial homogeneity. A finite element methodology (González, L. M., Theofilis, V., and Gomez-Blanco, R., ¿Finite Element Numerical Methods for Viscous Incompressible Biglobal Linear Instability Analysis on Unstructured Meshes,¿ AIAA Journal, Vol. 45, No. 4, 2007, pp. 840¿855) has been adapted to study the instability of vortical flows and has been validated on the Batchelor vortex (Mayer, E. W., and Powell, K. G., ¿Viscous and Inviscid Instabilities of a Trailing Vortex,¿ Journal of Fluid Mechanics, Vol. 245, 1992, pp. 91¿114). Subsequently, the instability of the counter-rotating dipole has been analyzed; aspects monitored have been the dependence of the results on the Reynolds number, the value of the (nonzero) axial velocity considered, and the time at which the quasi-steady basic flow has been monitored. Essential to the success of the analysis has been the appropriate design of a calculation mesh, as well as exploitation of the symmetries of the basic state. The spatial structure of the amplitude functions of all unstable eigenmodes reflects the inhomogeneity of the basic state in the azimuthal spatial direction, thus providing a posteriori justification for the use of the biglobal-eigenvalue-problem concept.
International
Si
JCR
Si
Title
AIAA JOURNAL
ISBN
0001-1452
Impact factor JCR
0,988
Impact info
Volume
46
10.2514/1.35511
Journal number
11
From page
2796
To page
2805
Month
NOVIEMBRE
Ranking
Participants
  • Autor: Vassilios Theofilis (UPM)
  • Autor: Rafael Gomez Blanco (UPM)
  • Autor: Leo Miguel Gonzalez Gutierrez (UPM)
Research Group, Departaments and Institutes related
  • Creador: Grupo de Investigación: Mecánica de Fluidos Computacional
  • Departamento: Motopropulsión y Termofluidodinámica
  • Departamento: Enseñanzas Básicas de la Ingeniería Naval
  • Grupo de Investigación: CEHINAV (Canal de Ensayos Hidrodinámicos de la E.T.S.I. Navales)
S2i 2020 Observatorio de investigación @ UPM con la colaboración del Consejo Social UPM
Cofinanciación del MINECO en el marco del Programa INNCIDE 2011 (OTR-2011-0236)
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